A disk type recording medium, such as a compact disc (CD) or a digital versatile disk (DVD), has been widely used as a portable information recording medium for a computer system, an audio/video recording/reproducing apparatus (disk player), and the like.
While some of such disk type recording mediums are loaded into a recording/reproducing apparatus while accommodated in a case or a kind of case called a caddy, etc., most disk type recording mediums used are loaded, with the disk main bodies thereof being exposed.
As a recording/reproducing apparatus (disk player) into which a disk is loaded in an exposed state, there are often used a so-called tray type apparatus and a so-called slot-in type apparatus.
The tray type apparatus is provided with a tray that can be moved by a carrying motor or the like so as to advance toward and retreat from a disk player for performing recording and reproduction on and from a disk. When loading the disk, the tray is caused to advance from the disk player, and the disk is placed on this tray. In this state, the tray is caused to retreat into the disk player. Through this operation, the disk is carried to a predetermined position in the disk player together with the tray, and clamped onto a hub or the like of a rotation mechanism to perform recording or reproduction on or from the disk.
In the slot-in type apparatus, there is used, in order to directly carry a disk without using any tray, a carrying mechanism composed of a slot allowing passage of the disk, a roller adapted to come into contact with the disk inserted into the slot, a carrying motor for rotating this roller, etc. When loading a disk into the apparatus, the peripheral edge of the disk is inserted into the slot. Then, the roller comes into contact with the back surface of the disk, and the roller is rotated by the carrying motor, whereby the disk is carried to a predetermined position.
Those two types of apparatuses only differ from each other in the carrying mechanism using a tray, a roller, etc. Regarding the rotation drive mechanism consisting of a hub of a rotation mechanism, a drive motor, etc. and a recording/reproduction mechanism which includes a pick-up or the like for recording and reproduction of information on and from a disk rotated by the rotation drive mechanism, substantially the same mechanisms are used in these two types of apparatuses.
In the above-described slot-in type disk player, it is necessary to reliably perform the following series of operations: to take in the disk through the slot by driving the roller by the carrying motor when a part of the disk is inserted through the slot; and to continuously move the disk along the carrying route to send the disk to a predetermined position in the disk player.
In general, the roller of the carrying mechanism of a conventional slot-in type disk player is formed as a bar arranged to extend along the slot, and is brought into contact with the back surface (i.e., recording surface) of the disk inserted into the slot.
The surface of the roller is entirely covered with a rubber-based material having high contact resistance, and the roller has a tapered configuration which is narrow at the center and is gradually increased in thickness toward both ends. Due to this construction, the roller comes into contact solely with small regions in the peripheral edge of the disk, and can reliably move the disk held in contact therewith through rolling. Due to this construction of the roller, the roller comes into contact with the recording surface side of the disk. However, the roller does not come into direct contact with the recording surface, thus minimizing the influence on the recording surface.
In the conventional slot-in type disk player, there is formed, on the side opposite to the roller of the carrying mechanism, a guide member for maintaining the disk in the carrying route.
To be more specific, a protruding portion swollen toward the disk carrying route is provided on a front panel member including a frame of the disk player or a slot opening, and this protruding portion comes into contact with the disk, which is pressed by the roller, from the opposite side to support the disk. Due to this contact, the carrying of the disk by the roller is reliably effected.
In order to conform to the frontage width corresponding to the insertion depth of the disk or to a difference in the disk size, the guide member is formed not as a simple protruding portion but as a rib construction extending in the same direction as the guide rail (i.e., a direction crossing the disk carrying direction).
In order to avoid an adverse influence on the disk surface (i.e., labeled surface) like wear, such a rib-like guide member is formed, if possible, so as to come into contact solely with the peripheral edge portion of the disk.
In view of this, the rib-like guide member is formed with a predetermined inclination such that it exhibits a large height (in other words, large protruding amount) at both ends of the slot and exhibits a small height in the middle portion of the slot, thus gradually increasing in height toward both ends (see, for example, Patent Document 1 and Patent Document 2).
In the conventional slot-in type disk player, it is necessary to start the carrying mechanism when a part of the disk is inserted into the slot. For this purpose, there is provided, in the disk player, a contact type detection mechanism on the inner side of the slot. In the case of CDs or the like, some of them have a diameter of approximately 12 cm, and the others 8 cm. This difference in size is also detected by the detection mechanism.
The detection mechanism has, for example, a guide rail installed so as to extend along the inner side of the slot, a moving member installed so as to be movable along this guide rail, a contact member in the form of a protrusion or the like formed on this moving member and adapted to come into contact with the peripheral edge of a disk, and a plurality of switches installed at predetermined positions along the guide rail and adapted to detect passage of the moving member.
Usually, the moving member with the contact member and the guide rail are arranged in a pair on both sides of the slot. Due to this arrangement in a pair, even if the center of the disk is somewhat deviated, it is possible to accurately detect the frontage width of the inserted disk as the distance between the contact members on both sides.
In the case of such contact switches, when the disk is inserted into the slot by a predetermined depth, the contact members are pushed open by the peripheral edge of the disk to a predetermined frontage width causing the carrying motor to start.
Part of the switches are installed at positions where they are turned ON/OFF when the predetermined frontage width causing the carrying motor to start is exceeded; through this turning ON/OFF of the switches, the carrying motor is started as a result of the insertion of the disk.
The guide rail is installed with a sufficient width so as to extend to the slot ends, and the contact member moves along the guide rail together with the moving member, opening by a width larger than the diameter of the disk being carried, whereby passage of the disk is not hindered.
Parts of the switches are set so as to be turned ON/OFF when the maximum width (i.e., diameter) of the passing disk is approximately 12 cm and when the maximum width is approximately 8 cm, whereby it is also possible to detect the size of the disk inserted.
[PATENT DOCUMENT 1] JP-A-2002-329359 (paragraphs 0003 and 0004, FIGS. 5 through 7)
[PATENT DOCUMENT 2] JP-A-2003-77198 (paragraphs 0014 and 0015, FIGS. 5 and 6)